The problem is that anybody who has those artistic skills to meet your requirements probably has the artistic imagination so that your designs and conceptualizations offer little or no benefit for them. And has already started one or more packs more to their personal taste.
This isn't the advice you want, but I suggest you try one of two things:
1) practice you artistic skills so you can create what you want. You already have a good start.
2) Contribute to somebody else's project, that's mostly congruent with your goals. You are a clear communicator, for instance.
The unvarnished truth is you don't bring enough to the table to for high-quality pixel artists to work for you. There is a greater demand for such pixel artist than there is a supply.